The present disclosure generally relates to a vehicle seat assembly, and more particularly relates to a rack and pinion arrangement for a vehicle seat assembly having a seat base and a seat back rotatably coupled to the seat base.
It is known to employ a fold-down seat back in a vehicle seat to provide increased cargo carrying capacity to a vehicle. Some vehicle seats use a fixed seat cushion with a pivotally mounted seat back. While simple in construction, a drawback of this arrangement is that the stationary seat cushion can interfere with fully folding the seat back to a horizontal position. With reference to FIG. 1, such a prior art vehicle seat assembly 10 is shown having a fixed seat base 12 and a seat back 14 pivotally mounted to the fixed seat base 12. As shown, the seat base 12 prevents the seat back 14 from being fully folded down into a horizontal position and thus a rear side surface 14a of the seat back 14 cannot be positioned so as to be coplanar with a cargo floor 16 arranged behind the vehicle seat assembly 10.
One solution proposed for dealing with this problem includes moving the cargo floor 16 up vertically so that the seat back 14 would not have to move to the fully folded position; however, this undesirably reduces cargo space between the cargo floor 16 and the roof (not shown) disposed in the vehicle above the cargo floor 16. Another proposed solution would be to move the body floor 18, on which the vehicle seat assembly 10 is mounted, vertically down thereby permanently lowering the seat base 12; however, such movement of the seat base 12 may not be possible for particular vehicle layouts because other components may be disposed below the seat base 12 and/or the body floor 18 (e.g., fuel tank, suspension components, etc.).
Other vehicle seats overcome the problems associated with the simple pivoting arrangement illustrated in FIG. 1 by employing a four-bar linkage to move the seat base and seat back relative to one another. For example, some four-bar linkage arrangements are used to lower the seat base simultaneously with movement of the seat back being folded down into a stowed position. Unfortunately, most current four-bar linkage systems are often complex and expensive.